Phentermine for more than 3 months?

Does anyone have information about what information may be useful to provide to my GP to if I am hoping she will prescribe Phentermine for more than 3 months? When I first got the prescription, it was discussed in terms of trying this for 3 months and then potentially switching to Wegovy (which is AUD$170 more per month and requires injections).

I have had a number of benefits from Phentermine for this first month, including:

• Fairly impressive weight lost so far with minimal effort (I need to fix the effort part - but have had a lot on),
• It has helped feel me feel more 'internally calm'/reduced the constant self-doubt and critical voice in my head,
• I'm sleeping better,
• It has reduced impulsive behavior (I haven't impulse bought Magic the Gathering cards since starting, I've only impulse binged junk food once),
• I don't feel achey and like a zombie when I wake up (this is not just from sleeping better - it includes when I have been up three times over night to look after my toddler).

I plan on sharing the above info with GP, especially given I am a bit concerned about changing to Wegovy, or worse - not being able to afford anything and losing all benefits.

I have seen people indicate that their GPs have prescribed Phentermine for longer than 3 months, and would be keen to get information on what has influenced that.

My resting heart rate seems to fluctuate between 'excellent' and 'above average' for my age (59-71).